Finding the Fourth Proportional to 12,321.40, 18,485.10 and 3,556.12

Step by Step Solution

1. Step 1: Write the proportion equation
   12,321.40 : 18,485.10 = 3,556.12 : x
2. Step 2: Convert to fraction form
   12,321.40/18,485.10 = 3,556.12/x
3. Step 3: Cross multiply
   12,321.40x = 18,485.10 × 3,556.12
4. Step 4: Simplify right side
   12,321.40x = 65,735,233.81
5. Step 5: Solve for x
   x = 65,735,233.81/12,321.40
6. Step 6: Final answer
   x = 5,335.05